Comparator for typewriting machine type



L. B. FULLER COMPARATOR FOR TYPEWRITING MACHINE TYPE June 26, 1951 4 Sheets-Sheet 1 Filed Aug. 20, 1946 Leon B. Fuller June 26, 1951 FULLER 2,558,078

COMPARATOR FOR TYPEWRITING MACHINE TYPE Filed Aug. 20, 1946 4 Sheets-Sheet 2 Inventor Leon B. Fuller 3 w ,Chw e Q At 95 June 26, L B, L E 2,558,078

COMPARATOR FOR TYPEWRITING MACHINE TYPE Filed Aug. 20, 1946 4 Sheets-Sheet 3 9 I 0 I m p I- N I o 1 I t N I 5?, co L m n IO 2 B 2 q I i\ g I I I 1 i l I I I f I I I I l I l l I I I I I l l I I I I l I I I l I I I I I l l I I I x Inventor Leon B. Fuller EI- Qua-m Att s June 26, 1951 B. FULLER COMPARATOR FOR TYPEWRITING MACHINE TYPE Filed Aug. 20, 1946 4 Sheets-Sheet 4 Inventor Leon B.Ful\er b. 3mm, QMAAIjVWNi Attlj Patented June 26, 1951 COMPARATOR FOR TYPEWRITIN G MACHINE TYPE Leon B. Fuller, Springfield, Vt., assignor to .lones & Lamson Machine Company, Springfield, Vt.,

a corporation of Vermont Application August 20, 1946, Serial No. 691,685

3 Claims. 1

This invention relates to apparatus for checking up on the alignment of type blocks in a typewriting machine. Such blocks are secured on the ends of type bars which are pivotally mounted on a type segment in the typewriting machine, suitable linkages connecting the type bars with the keys of the machine so that when any individual key is depressed, the corresponding type bar is swung about its pivot to bring its type block against the platen roll of the machine. When a set of type bars has been assembled on a type segment, it is usually necessary to make small adjustments by suitably bending the individual type bars so that when the type faces on the blocks hit against the platen roll, the impressions will be upright and will be horizontally aligned and the pressure evenly distributed over the face of the type. If these adjustments are properly made, the lines of writing will be straight and not irregular, and the individual characters of uniform color depths throughout.

It is an object of the present invention to provide means for easily and accurately observing whether the type bars are correctly shaped so that the type faces will strike accurately against the platen roll when keys of the machine are struck. If any individual type block is not in correct position, its type bar may be slightly bent and another observation can be made to determine whether the new position of the type block is within the limits of tolerance.

In order to determine whether a type block is in its correctposition when it reaches its striking position, I provide a means for mounting a complete type segment on the work table of a comparator of the general type described and illustrated in the patent granted to Hartness and Porter, March 5, 1929, No. 1,703,933. This patent shows a bench type comparator having a work table to support an object to be observed or tested in a predetermined position. A beam of light is projected past a portion of a profile of the work piece and a shadow image of this portion of the profile is focused upon a translucent screen which is conveniently located above and behind the work table.

According to the present invention, a work holder is adjustably mounted on the table of a comparator and is adapted to support a type segment in the same manner in which such type segment is to be supported in the typewriting machine for which it is made. The type segment includes a bracket having a guide member for the type bars, the purpose of the guide memher being to receive any one of the' various type bars which is swung up to its striking position and to ensure the type block being in its proper position when it strikes the roll platen. When a type segment is mounted on the work holder and a type bar is swung up to engage in the throat of the guide member, the type block on that bar is then in position for testing. According to the invention, the comparator is equipped with a lamp arranged to project a beam of light across the front face of the type block from one side so that a profile shadow image of the front face is produced. This shadow image is reflected and focused upon the translucent screen which is mounted in the front wall of the comparator housing aboveand to the rear of the work table. In addition to the shadow image of the profile of the front face of the type block, a direct image of this front face is also focused upon the screen. For this purpose, the work holder is so arranged as to locate the type block in line with a lens system through which the image of the front face of the type block is focused and cast on the screen beside the shadow image. The direct image requires adequate illumination of the front face of the type block. Hence, according to the invention, provision is made to reflect light against the front face of the type and, as shown, this is done by mirrors mounted adjacent to the lens system to reflect beams of light from two lamps so that these, beams converge at a small angle on the face of the observed object in the manner described in Patent No. 2,031,201, granted February 18, 1936.

For a more complete understanding of the invention, reference may be had to the following description thereof and to the drawings, of which:

Figure 1 is a front elevation of the lower portion of a comparator embodying the invention;

Figure 2 is a plan View of the forward portion of the comparator shown in Figure 1;

Figure 3 is a section of the entire comparator on the line 33 of Figure 2;

Figure 4 is a front elevation of the screen or chart on which the images of the work piece are thrown;

Figure 5 is a side elevation, partly broken away to show in section a modified form of support for the work piece;

Figure 6 is a front elevational view of the same;

Figure 7 is a plan view of the same.

The comparator illustrated on the drawings comprises a bed or base II) which supports a housing l2 on the rear portion and a work table H on the front portion thereof. The work table [4, as indicated in Figure 1, may be somewhat offset from the center of the comparator and may be adjustable forwardly and rearwardly on a dove tail slide IS. A finger wheel I8 on a screw threaded shaft 2D is conveniently located for shifting the. work table so as to adjust the object to be tested or observed toward or from the'housing l2. In this way the distance of the work table from the lens holder 16 can be regulated.. Suitable set screws 22 may be provided to lock the table I4 in any of its positions of adjustment; On the central portion of the work table I4:is H mounted a work holder 24 whichis providedwith two uprights 26 and 28 to the upperends .of which a type segment for a typewriting machine may be secured by means of screws 30 and 32 which enter holes in the typesegmentadapted to receive screws by which the segment willvbe secured to the frame of a typewriting machine. A type. segment 34 of the kind designed to be 7. supported. by the work holder ,24 is illustrated in Figures 6 and? and comprises an arcuate mem. ber 36to Which a set of type ba'rs 38'is secured, each type bar being independently pivotednea-r' one end so as to bring its otherend portion into the throat of a guide member-4B which is mounted on the type segment forthe purpose of guiding, type blocks to their correct striking position againstthe platen roll ofthe typewriting machine in which the type segment is to be installed. Each type bar 38 has a type block 42'mounted at its free extremity,this type block being immeev diatelyhabove the guide member 49 when the type bar is swungup to its striking position.

The work holder isiadlustable on the work table'and is secured in position by suitable'set screws 44; As'indicated in'Figure l, a lamphouse 4B is mounted on a standard 48 at a right hand I end of thework table I4;the lamp house beingac in .a position to support a lamp 56 on a level .i' with the type block '42which is to be tested or; inspected. The lamp. house 46 is provided with a lens holder 52 within which is a collimating lens adapted toproject a horizontal beam of 4: parallel light rays across the front face of the typeblock 42 from a side thereof. To'theleft" of'the work holder i4 is a mirror 56 supported. on a standard 58 which is adjustable toward or, from the work table 24 by means of a screw 60; 1 The mirror 55, as indicated in Figure 2,,is ar.. rangedto reflect the shadow image of the type. block '42 through an angle. of .90f"'so that the. light beam defining this shadow" image willMbe sent through a window 52 in an aperture inthe. front wall of the ,housing !2. Associated with. the mirror 56 are suitable lenses mounted inlens holders 64 and 56 for focusing. and magnifying the shadow image of the type block 42 upon the screen it which is mounted in a large circular 60 aperture in theupperportion of the front wall of the housing 12. The light beam which enters the housing through the window 62 is reflected. back by a mirror '52 adjustably mounted within the housing l2 at the rear thereof so that the. reflected light strikes the rear surface of. .the...-, translucent screen it and shines through. the screen.

When a type block 42 is in the positionforf testing, .it faces the housing. Opposite tothe 79 type face is an elongated lens holder 16 which, projects through an aperture in the front wall of the housing. I2 and supportsa system-of -lenses bywhich an image of the front face of thetype..

block.Alisenlargedand focused .on the screen is '10. The lens holder 16 is laterally offset from and on a level with the window 62, these two members being below the screen 10 and preferably equidistant from the center line of the comparator. In order to provide adequate illumination of the front face of the type block 42, a pair of mirrors BB and 82 are mounted on either side of: the exterior portion of the lens holder 76. On a level with these mirrors a pair of lamp houses 84 and 86 are mounted on the front wall of the housing I 2 and are equipped with collimating lenses-88. adapted to project beams of light against the mirrors and 82 so that the beams willberefiectedto the type face of the type block 42; thesebeams converging on the type block at a small angle as indicated in Figure 2. As a result of the considerable intensity of light directed t0 the-type---face of the type block 42, the image of this type face is sufficiently bright on the screen 10 even though greatly magnified.

Figure 4 is an, elevational view of the screen 10 showing thereon the front, and profile images of ,the face of a typeblock. The screen lfl'is preferablyiproyided with suitable'horizontal reference lines .90 adapted to indicate the proper elevation of the typeblock 2 and to show boundaries withinwhich the horizontal portions of bothfthe'capitals and the lower caseletters, on the vtype b1ock should appear. Thus errorsin 7 the, type face, itself, aslvwell as in the position of the type, block, are easilydetected. Arcuate linesof reference 92 are also provided on the screen H! tobe fitted by the arcuate profiles of the type face on the type block if the type block is in its correct position, the curvature of. the

type faces being complementalutol that of the platen roll sothat all portions of thetype face will strike the platen roll with uniform pressure.

Vertical lines 914 are, also provided to assist in observing any. lateral orjangular displacement .of j

the type block i42ffl'Omlts correct strikinspqsition. Since thetype blocks are greatlymagnified on this screen, the orderof magnification being 20;any slight variations ofform or position of the type'blockfrom its correctform and striking. position are quickly and easily noted and slight bends can be made injthe type barwith suitable.

tools until additionalinspections show the type block to-be properlylocated If desired, the work holder can be made rotatably' adjustable'about a .verticalaxis. For this purpose the construction thereof can beas illustrated in Figures 5, 6 and '7. As therein shown, the holder I24 is provided with a central spindle I26 which fits in the holethrough a base, H8.

The Work holder [24' canbe verticallyadjusted by means of a pair ofyscrews I30, the lower ends of i which bear on the upper surfaceof the base I28;

Relative rotation between the work holder I 24'a'nd the base I28fisprevented by a suitable pin I32f which extends through the lower part of the.

holder- I24. and. the base .125. The. base. has a cylindrical projection. I 34 coaxial with the spindle 26 so that the holderand base can be rotatably 5. adjusted ,asa unit by releasinga locking screw 136 which extends through an .arcuate'slot I38 into the work table 14.0. Whenthe work holder I24 has beenadjusted to itsdesired angular position, the'locking screwl3$- is set up to clamp the work holder insuch-position What I claimis:

1.;In a comparatorhaving a work tab1e :and;a

translucent screen, means ,on said table for supporting-a type segmentof a typewriting machine so that when any individual-type; block thereof is swung to its striking position it will be in position for testing, and means for projecting on said screen simultaneously enlarged images of the front face and profile of a type block in said position for testing, said projecting means including a lamp and lens system mounted on said table and arranged to project a beam of light across the front face of said type block from a side thereof, means for projecting beams of light upon said front face, and optical means for magnifying and focusing on said screen the shadow image of said profile and the illuminated image of said front face.

2. In a comparator having a bed, a housing on said bed, a work table adjustably mounted on said bed in front of said housing, said housing having a front wall with a translucent screen mounted in the upper portion thereof and two small apertures below said screen, a work-holder mounted on said table, means on said table for projecting a beam transversely past the work carried by said holder in position to be tested, means for reflecting said beam and the shadow image of the work through one of said apertures in the front wall of the housing, means mounted on said housing for projecting converging beams of light upon the work in said position to be tested, a lens system for transmitting through the other aperture of said front wall and focusing reflected light from said work, and means within said housing for simultaneously reflecting to spaced portions of said screen the beams entering said housing through said apertures.

3. In a comparator having two apertures in the front wall thereof and a translucent screen above said apertures, a lens holder mounted in and extending through one of said apertures, an objective lens system in said lens holder, a Work table adjustably mounted in front of said wall, a work-holder on said table including means for holding an object to be tested in line with said lens holder, two light sources mounted on said housing on either side of said lens holder, collimating means for directing beams of parallel rays from said sources toward each other, mirrors carried by said lens holder and arranged at angles to reflect said light beams toward said object, a third light source mounted on said table and arranged to project a horizontal light beam at said object in a direction parallel to said front wall, a lens holder containing an objective lens system and a mirror mounted on said table in line with said last mentioned light beam and directly in front of the other said aperture, and a mirror within said housing adjusted to reflect to the said screen the light beams entering through both said apertures.

LEON B. FULLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 505,127 Ranger Sept. 19, 1893 1,377,068 Hartness May 3, 1921 1,421,042 Twyman June 27, 1922 1,589,349 Bausch et a1 June 22, 1926 1,687,946 Mossic Oct, 16, 1928 1,703,933 Hartness et a1 Mar. 5, 1929 1,789,009 Luce Jan. 13, 1931 2,031,201 Beardsley Feb. 18, 1936 2,035,780 Beardsley et a1 Mar. 31, 1936 2,192,529 Thomas et a1 Mar, 5, 1940 

